scope: implemented waveform scope

app/shaders/rgbwaveform.frag

@@ -0,0 +1,29 @@
+// Adapted from "RGB Waveform" by lebek
+// https://www.shadertoy.com/view/4dK3Wc
+
+#version 110
+
+uniform sampler2D ove_maintex;
+uniform vec2 ove_resolution;
+varying vec2 ove_texcoord;
+
+uniform float threshold;
+
+void main(void) {
+    vec3 col = vec3(0.0);
+    float s = ove_texcoord.y*1.8 - 0.15;
+    float maxb = s+threshold;
+    float minb = s-threshold;
+    
+    int y_lim = int(ove_resolution.y);
+
+    for (int i = 0; i < y_lim; i++) {
+        vec3 x = texture2D(ove_maintex, vec2(ove_texcoord.x, float(i)/float(ove_resolution.y))).rgb;
+        col += step(x, vec3(maxb))*step(vec3(minb), x) / (ove_resolution.y * 0.125);
+
+        float l = dot(x, x);
+        col += step(l, maxb*maxb)*step(minb*minb, l) / (ove_resolution.y * 0.125);
+    }
+
+    gl_FragColor = vec4(col, 1.0);
+}